The invention relates to analog circuits in an integrated circuit environment and, in particular embodiments, to low voltage integrated circuits having both digital and analog components.
As higher levels of circuit integration are achieved more analog functions are being mixed with digital functions on the same integrated circuit. In addition, as circuit dimensions shrink, integrated circuit supply voltages decrease. There is therefore a need in the art for techniques to facilitate the use of lower voltages in mixed integrated circuits.
The invention discloses apparatus for providing programmable gain attenuation or amplification (PGA) for electrical signals. An example PGA, according to an embodiment of the invention comprises a plurality of impedances arranged in series. The junctions of the series impedances forms taps. The taps are coupled to a plurality of terminating resistors. By coupling the terminating resistors to a ground the PGA can be programmed.